"Which flea med?" is one of those tricky questions, with as many different answers as there are pet parents! The answer also depends on the age/weight of the dog in question. I remember we tried a couple different brands/types of both flea/tick prevention and heartworm meds as our puppy grew in and out of different age/weight brackets, until we finally settled on the one we had been aiming for originally (Sentinel)... only to have that one discontinued (well, suspended indefinitely) by the manufacturer, leaving us to go through the process all over again!
I don't have any personal experience with either of the meds in question, but looking at product info found on online pet supply stores, I see that the Comfortis pill says not to give to puppies younger than 14 weeks, so you wouldn't be able to start your new furbaby on that for another month or so.
As for the Certifect, according to product info, it's safe for puppies 8 weeks and older, as long as they weigh at least 5 lbs. So as long as your little guy weighs more than that (our puppy didn't at that age), you'd be fine there... as long as you don't have any cats in the house. Certifect contains amitraz, which I understand to be highly toxic to cats.
The best thing to do would be to discuss it with your vet, I think, when you bring the new puppy in for his/her initial check-up in the next few days... especially if you are looking to use both Comfortis AND Certifect (which is how I interpreted what you meant by your vet tech friend's recommendation of both products). Your vet would be able to determine if either (or both) of these products would be appropriate for your situation, and if not, suggest an alternative in the interim.
Congrats on the new puppy... be sure to post lots and lots of pictures!
